[复习说明 ]数学开放性问题 ,或是由给定的条件寻求相应的结论 ,或是由给定的结论反溯应具备的条件 ,或是判断符合条件的某种数学“对象”是否存在 ,或改变命题的条件或结论的某一部分来探求整个命题将发生什么变化等 .数学开放性问题的一个明显特征是探索性 ,解答开放性问题对 [Review Instructions] The question of mathematical openness, either to seek corresponding conclusions from a given condition, or to reconstruct the conditions that should be possessed by a given conclusion, or to judge the existence of certain mathematical “objects” that meet the conditions, Or change a certain part of the conditions or conclusions of the proposition to explore what changes will occur in the entire proposition. An obvious feature of the open question of mathematics is exploratory, to answer open questions.